Cooling system for electron tubes and other devices



July 5, 1949. w. E. BROWN 5,

COOLING SYSTEM FOR ELECTRON TUBES AND OTHER DEVICES Filed Jan. 10, 1947Kh i 6 CONTROL.

BOX

Patented July 5, 1949 COGLING SYSTEM FOR ELECTRON TUBES AND OTHERDEVICES William E. Brown, Pewaukee, Wis., assignor to Cutler-Hammer,Inc., Milwaukee, Wis., a corporation of Delaware Application January 10,1947, Serial No. 721,325

9 Claims.

This invention relates to fiuid cooling systems for electron tubes andother devices, and more particularly to improved protective means whichdetects and responds to cooling system abnormalities.

An object of the invention is to provide simple and inexpensiveprotective means which responds to temperature and coolant flow rateabnormalities.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings show an embodiment of the invention, it beingunderstood that the embodiment illustrated may be altered in variousways without departing from the scope of the appended claims.

In the drawings,

Figure 1 is a schematic showing of a cooling system for an electrontube, which incorporates the improved protective means;

Fig. 2 is a vertical sectional View of a part shown in Fig. 1,sectioning being along line 2-.-2, Fig.

Fig. 3 is a horizontal section along line 33, Fig.

Fig. 4 is a perspective view of a bimetallic element shown in Figs. 2and 3.

Referring to Fig. 1, this shows an electron tube l and protective meanstherefor comprising a switch 2 under the control of a bucket typevariable weight 3. Tube I, assumed to be of a known liquid cooled type,has a coolant inlet 4 and an outlet 5. It also is shown as having ananode lead 6, a cathode lead I and an igniter lead 8.

A housing 9 of suitable metal or plastic construction is provided forsupporting the switch 2 and for enclosing said switch and the variableweight 3. The housing 9 shown only in vertical section may be assumed tobe circular in cross section. The top of the housing is preferablyclosed except for a hole provided to receive a pipe -l| projecting intothe interior of the housing. 'Pipe H is connected to the outlet 5 oftube I. The bottom .of the housing 9 is closed except for an outlet l2from which leads a Waste pipe 13. The housing 9 and pipe I l arepreferably secured together as by brackets within the housing havingstraps l4 and I5 embracing and clamping that portion .of pipe H whichprojects into the interior of the housing. Preferably the pipe II islocated substantially coaxially with the lower portion of the housing.

The .protective switch ;2 shown as enclosed, is fastened to the housingin a suitable position as by screws I1 and I8 threading into a Wall ofthe housing or a bracket thereon. Terminal screws l9 and 20 are providedfor electrical connection of the switch 2 in any of the well knownprotective relations to the tube 1. The switch has an actuator button 2|which is normally biased in one direction by a spring lever 22. Thelever 22 is a flat strip of spring metal and is fastened to the housingof the switch as by screw 23. It has a hook or groove 24 at its free endwhich forms a saddle for supporting the bail 25 of the bucket typeweight 3.

Under normal conditions with little or no weight exerted downwardly onthe end of the lever 22, said lever flexes to move the switch 2 into agiven position through the medium of the actuator button 2!. Switch 2may be assumed to be a so-called microswitch biased to a given positionand movable into another position through the medium of button 2|. As iswell known, switches so designated are capable of handling substantialcurrents while requiring only very minute move ents of their actuators.Such switches are commercially available in various types and sizes.

The variable weight 3 comprises a thin walled cylindrical bucket 26constructed of a light metal and containing a bimetallic sleeve 27, saidbucket being suspended to receive the discharge of coolant from pipe H.Bucket 2.6 has a plurality of holes 29 drilled through its cylindricalwall near the bottom thereof, said holes preferably being evenly spaced.The bimetallic sleeve 21 is mounted inside the bucket with its outerside conforming to the inside circumference of the bucket wall totightly cover the holes 29.

Referring to Fig. 2, it shows the bucket in vertical cross section andshows a preferred form of bail 25 hooked into small holes 30 and 3i andhaving free pivotal movement therein. Fig. 2 also shows the bucket ashaving a small hole or orifice 32 in the bottom wall thereof.

Referring to Fig. 3, it shows the bucket in horizontal cross section andshows in full lines the bimetallic sleeve 21 in its normal statepressing against the bucket wall. Sleeve 21 is preferably fastened tothe bucket wall near one end as by rivet 33.

Reierring to Fig. 4, this shows in perspective a preferred form of thebimetallic sleeve 21. The drawing is exaggerated in respect to thethickness of the sleeve to more clearly indicate its bimetallicconstruction. The sleeve is fabricated from a thin strip of bimetal andshaped in the form of a circular band with overlapping ends. The sleeveis so formed that the metal having the high coefiicient of expansion ison the outside circumference. It is sized to conform to the internalcircumference of the container at normal temperatures. Increasing thetemperature above normal will cause the sleeve to de crease incircumference, and conversely the sleeve will tend to increase incircumference when the temperatures are below normal.

When the bucket has no liquid therein its weight will be insufficient torelieve the force exerted on the actuator button 2| by the lever 22. Theswitch above described will thus be retained in a given position, whichmay be open position or closed position, as preferred. However, when thecooling system is in operation and the normal rate of coolant iscirculating about the electron tube I the coolant will be dischargedinto the bucket 26 through pipe I Coolant will normally accumulate inthe bucket to a certain level, with excess coolant passing out throughthe orifice 32. The added weight of the accumulated coolant reduces theforce exerted by the lever 22 on the actuator button 2| sufiiciently tocause the switch 2 to move to its normal position, thereby permittingthe operation of the electron tube I. If the rate of coolant flow fallsbelow a predetermined rate, the rate of coolant flow from the bucketthrough the orifice 32 will be sufiicient to reduce the weight ofaccumulated coolant below the value required to restrain the lever 22from biasing the actuator button upwardly, thereby actuating the switchvThe liquicl flowing from the bucket 26 is discharged to a sewer by thewaste pipe l3 or can be recirculated through a closed cooling system.

Under normal operating conditions with normal rate of coolant flow beingmaintained, the temperature of the coolant will be such that thebimetallic sleeve 21 will conform to and exert a pressure against thebucket wall to close the holes 29, thereby preventing any appreciableescape of coolant through these holes. The bucket 26 can be adjusted tomaintain the same weight of accumulated liquid at a different normalflow rate as by changing the size of the orifice 32.

If the temperature of the coolant fluid leaving the tube I shouldincrease above a certain Value due, for example, to abnormal electricalloads on the tube the sleeve 21 wil respond to the increase intemperature of the coolant and will contract away from the bucket wall,thus permitting coolant to escape from the bucket at an increased ratethrough the holes 29. This reduces the weight of accumulated coolant inthe bucket and a given reduction in weight thereof permits the lever 22to bias the actuator button 2| upwardly, thereby actuating the switch asabove described.

The above described protective means is simple and yet affords adequateprotection against coolant temperature flow rate abnormalities.

What I claim as new and desire to secure by Letters Patent is:

1. In apparatus responsive to abnormality of a stream of liquid, thecombination with a yieldingly mounted container supplied with liquid ata rate varying with the rate of flow of the aforementioned stream, saidcontainer having an outlet for the liquid therewithin, of means toregulate the outlet of said container, said means comprising thermallyresponsive means subjected to thei mal conditions varying with thetemperature of liquid in said container.

2. In apparatus responsive to abnormality of a stream of liquid, thecombination with a. yieldingly mounted container supplied with liquid ata rate varying with the rate of flow of the aforementioned stream, saidcontainer having an outlet for the liquid therewithin, of means toregulate the outlet of said container, said means comprising thermallyresponsive means subjected to thermal conditions varying with thetemperature of liquid in said container, and said container affordingthe liquid therewithin a given outlet free from restriction by saidthermally responsive means.

3. In apparatus responsive to abnormality of a stream of liquid, thecombinations with a yieldingly supported container supplied with liquidat a rate varying with the rate of flow of the aforementioned stream,said container having an outlet for the liquid therewithin, of means toregulate escape of liquid from said container, said means comprisingthermally responsive means subjected to thermal conditions varying withthe temperature of the liquid in said container, thereby to accelerateor retard escape of liquid according to the temperature of liquid insaid container, said container under the control of said regulatingmeans aifording escape of liquid such as to establish and maintaintherewithin a given liquid level and thus to assume and maintain a givenposition if and While supplied with liquid at a given rate and a giventemperature but subject to change in such liquid level and to change inits position as a function of changes in either rate of flow ortemperature of the liquid supplied thereto.

4. In apparatus responsive to abnormality of a stream of liquid, thecombination with a yieldingly supported container supplied with liquidat a rate varying with the rate of flow of the aforementioned stream,said container having an outlet for the liquid therewithin, of means toregulate escape of liquid from said container, said means comprisingthermally responsive means subjected to thermal conditions varying withthe temperature of the liquid in said container, thereby to accelerateor retard escape of liquid according to the temperature of liquid insaid container,

. said container under the control of said regulating means affordingescape of liquid such as to establish and maintain therewithin a givenliquid level and thus to assume and maintain a given position if andwhile supplied with liquid at a given rate and a given temperature butsubject to change in such liquid level and to change in its position asa function of decrease in rate of flow of the liquid supplied orincrease in tempera ture of such liquid.

5. In apparatus responsive to abnormality of a stream of liquid, thecombination with a yieldingly mounted container supplied with liquid ata rate varying with the rate of flow of the aforementioned stream, saidcontainer having an outlet for the liquid therewithin, of means toregulate the outlet of said container, said means comprising thermallyresponsive means immersed in the liquid in said container and subjectedto the variations in temperature of said liquid.

6. In apparatus responsive to abnormality of a stream of liquid, thecombination with a yieldingly mounted container supplied with liquid ata rate varying with the rate of flow of the aforementioned stream, saidcontainer having an outlet for the liquid therein, of a bimetallic stripsubjected to the temperature of the liquid in said container andoverlying the outlet in said container to close or open said outlet as afunction of change in the temperature of the liquid.

7. In a cooling system the combination with conducting means for a flowof coolant liquid, said means including a movably mounted element whichassumes difieren't positions according to the quantity of coolant liquidaccumulating therein, of means for rendering the escape of liquid fromsaid element variable with the temperature of coolant liquid in saidelement and protective means under the control of said element.

8. In a cooling system the combination with conducting means for a flowof coolant liquid, said means including a movably mounted containerwhich assumes different positions according to quantity of coolantliquid accumulating therein, of thermally responsive means immersed inthe coolant for varying the rate of escape of liquid from said containerin accordance with the temperature of the coolant liquid in saidcontainer and protective means under the control of said container.

9. In a cooling system the combination with conducting means for a flowof coolant liquid, said means including a movable mounted containerwhich assumes different positions according to the quantity of coolantliquid accumulating therein, of a thermostatic device for varying theeffective opening of an outlet in said container for rendering theescape of liquid from said element variable with the temperature of thecoolant liquid in said container and a protective device under thecontrol of said movable container to assume selectively two difierentpositions,

WILLIAM E. BROWN.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 951,563 Hatch Mar. 8, 19101,420,045 Lippert June 20, 1922 1,951,697 Klein Mar. 20, 1934 2,157,470Adlam May 9, 1939 FOREIGN PATENTS Number Country Date 9,861 GreatBritain 1906

